Gully+KWP in my conservatory!

[patrickm]

Hi,

I moved into our terraced property about 6 months ago, it has a 3m deep sloped-roof conservatory along the whole back of the building, built approx 5 years ago.

Unfortunately, the cheapskates who build it left the gully / KWP in-situ, simply boxing it in to the wall and providing an access panel.

This is a problem for a number of reasons -
1) it probably doesn't conform to building regs.
2) it smells!
3) it means we don't have an outside gully that would allow us to easily install an outside tap and to take rainwater from the roof.

I can't see a manhole cover anywhere outside, so I'm not sure how this drains into the public sewer. Would it be under the house?

I have thought about possible solutions to this - the conservatory floor is tiled, probably directly onto a concrete base. (no insulation, cheapskates!) I guess the proper way to rectify this would be to dig up the floor an lay a pipe out of the conservatory and a new gully at the back of the property?

We are also about to build a patio at the back of the building, but without a gully the roof's rainwater is draining out of a downpipe with a short horizontal section about 1m from the house, direct into the soil (previously crazy paving) on the boundry of our property.

Would it be sensible to dig a narrow-ish trench along our boundry, next to the patio, sloping towards the garden, filled with hardcore and topped with gravel to drain this water away? What alternatives are there?

I definitely feel like we are currently paying for the previous owner's shortcuts, but I want to make sure we do it right!

Thanks in advance,

Patrick

[84-1093879891]

I'm late - been away - sorry


I can't be certain about the drainage layout at your property, but it's pretty unlikely that the drianage runs under the house itself. There is probably a common sewer running along the back of your property (and the neighbouring properties) collecting sewage and surface water in one. There may not be a MH or IC as, with older properties, many connections were simply made directly into the sewer and if access was required, it was assumed that rods could be sent down the gullies and/or other fittings.

So, before you start digging-up the conservatory floor, I'd have a nosey around the back gardens of neighbouring properties to see if you can spot any MHs or ICs which will indicate the position of the common sewer. In virtually every case involving these terraced properties, the common sewer runs parallel to the building line, usually 2-3 metres out.

Once you know where the sewer is located (and it may well be directly under your conservatory) you can decide on your next move. It may be simpler to permanently seal the problem KWP and use boxed-in 40mm grey waste pipes to direct effluent from the kitchen to a new hopper or KWP installed outside the conservatory, but, until you know where that sewer is located, it's all speculation.

The same goes for the surface water drainage. There is an outside chance that there is a separate SW system - most terraced properties used a combined system, but until you know where it is....

Assuming you can't install a SW gully for your paving and the conservatory roof, then a land drain and/or a soakway may be a sensible option, but again, I'm guessing as I'm not familiar with your layout.

Try to have apoke about to see what drains/sewers are present and then you can plan your new drainage fittings.


Good luck!

[patrickm]

Thanks for the reply Tony, no worries about the delay!

I'll have a nosey around tonight to see if I can find the sewer location. I think it may even have been drawn on the deeds of the house / water search, if I can find them! I like your idea of just sealing the existing KWP / gully and re-routing the kitchen waste to a new outdoor KWP.

I'm almost certain there's not a separate SW system, so in this case what would be the best type of gully to install that could accomodate both the kitchen waste and the surface water? Also, how do I go about attaching this to the existing sewer?

I assume there's plenty of info around the site, so I'll get reading!

[84-1093879891]

To replace the existing KWP with a combined KWP and SW gully, go for a trapped Access Gully. These allow you to force rods down their gullet, in case of any problems, but are relatively small and discreet.

To connect yup to the existing sewer, I'd say the best method is to install a new Access Chamber (once you find the sewer line) and then pipe-up to that. Putting in a new AC may seem like a lot of work, but it's no harder than fitting a new junction, and it ensures that, if you want to add any other drainage fittings, you can leave 'tails' or 'spurs' that can be utilised at a later date.

[patrickm]

Damned house! I looked in both my garden and the 2 to either side for ANY evidence of the sewer line but couldn't find any. Very frustrating!

I'm going to have to find the water company search which I'm sure had a diagram of the sewer location.

Typically how deep is the sewer? 1m? Seems like quite a big job to fit an Access Chamber, and I've had no experience of sewer / drainage work. I will have to weigh up my options I think!

Thanks for the replies and the great help you provide to everyone!

Patrick

[84-1093879891]

On older properties, the common sewer is usually 1.2-1.8m deep.

Have you asked any of the neighbours if they have any ideas, or if they have IC's, MHs etc in their back yards?